[Intel-gfx] [PATCH v4 4/5] drm/i915: Clarify flow for disabling IRQs on storms

[Ville Syrjälä]

On Mon, Nov 05, 2018 at 05:20:10PM -0500, Lyude Paul wrote:
> This is rather confusing to look at as-is:
> dev_priv->display.hpd_irq_setup(dev_priv); in intel_hpd_irq_handler()
> handles disabling the actual HPD IRQ, while
> intel_hpd_irq_storm_disable() handles moving the HPD pin state over from
> MARK_DISABLED to DISABLED along with enabling polling for it.
> 
> Changes since v3:
> - Rename i915_hpd_irq_storm_disable() to
>   i915_hpd_irq_storm_switch_to_polling() - Rodrigo Vivi
> 
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Lyude Paul <lyude at redhat.com>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/intel_hotplug.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c
> index c11d73de16f2..d642c0795452 100644
> --- a/drivers/gpu/drm/i915/intel_hotplug.c
> +++ b/drivers/gpu/drm/i915/intel_hotplug.c
> @@ -161,7 +161,8 @@ static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv,
>  	return storm;
>  }
>  
> -static void intel_hpd_irq_storm_disable(struct drm_i915_private *dev_priv)
> +static void
> +intel_hpd_irq_storm_switch_to_polling(struct drm_i915_private *dev_priv)
>  {
>  	struct drm_device *dev = &dev_priv->drm;
>  	struct intel_connector *intel_connector;
> @@ -351,8 +352,8 @@ static void i915_hotplug_work_func(struct work_struct *work)
>  	hpd_event_bits = dev_priv->hotplug.event_bits;
>  	dev_priv->hotplug.event_bits = 0;
>  
> -	/* Disable hotplug on connectors that hit an irq storm. */
> -	intel_hpd_irq_storm_disable(dev_priv);
> +	/* Enable polling for connectors which had HPD IRQ storms */
> +	intel_hpd_irq_storm_switch_to_polling(dev_priv);
>  
>  	spin_unlock_irq(&dev_priv->irq_lock);
>  
> @@ -458,6 +459,10 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv,
>  		}
>  	}
>  
> +	/*
> +	 * Disable any IRQs that storms were detected on. Polling enablement
> +	 * happens later in our hotplug work.
> +	 */
>  	if (storm_detected && dev_priv->display_irqs_enabled)
>  		dev_priv->display.hpd_irq_setup(dev_priv);
>  	spin_unlock(&dev_priv->irq_lock);
> -- 
> 2.19.1

-- 
Ville Syrjälä
Intel